# Swine Finishing Barn Layout and Space Requirements ## Key Takeaways - **Space allowance is critical for performance and welfare:** For pigs reaching 270-280 lbs, allocate 8-10 sq ft per pig; for heavier market weights (near 300 lbs), increase to 9.5-11 sq ft. Understocking leads to increased aggression and reduced feed/water access, impacting daily gain and feed efficiency. - **Pen dimensions and configuration influence pig behavior:** Pens should ideally be 10-20 ft wide and 12-30 ft long, with a length-to-width ratio promoting distinct lying and dunging areas. Solid partitions up to 2-3 ft reduce disease transmission and aggression. - **Ventilation management is paramount for respiratory health and thermoregulation:** Minimum cold-weather exchange is 20-30 CFM/pig to manage moisture and gases, while hot-weather ventilation requires 200-300 CFM/pig for heat removal, utilizing mechanical (negative pressure, tunnel) or natural systems. - **Feeder and drinker provision directly impacts feed intake and growth:** Provide one feeder opening per 4-5 pigs for dry feeders or 8-10 pigs for wet-dry feeders, and at least one nipple drinker per 10-12 pigs, ensuring placement away from lying areas and at appropriate shoulder height. - **Biosecurity protocols, including all-in/all-out flow and a defined clean-dirty line, are essential to prevent disease introduction:** Design for a boot wash station, dedicated loadout areas, and strict adherence to protocols to minimize pathogen transmission between groups and external sources. - **Flooring choice impacts hygiene and pig comfort:** Fully slatted concrete floors with 1-inch slot widths are standard for finishing pigs, facilitating manure removal; plastic or wire mesh is less durable for heavier finishing weights. --- Planning a swine finishing barn is one of the most consequential decisions you will make as a pork producer. The layout you choose and the space you provide per pig directly affect daily gain, feed efficiency, animal welfare, labor requirements, and your bottom line for years to come. This guide covers the full planning process for a grow-finish facility, from understanding pig growth patterns and space allowances to designing the floor plan, ventilation system, manure handling, and feeding and watering layouts. It is written for independent producers, farm managers, and anyone planning a new barn or remodeling an existing one. We will walk through the key decisions in order: determining your target market weight and pig flow, calculating space per pig, choosing pen size and configuration, designing alleys and gates, planning feed and water systems, and selecting a ventilation approach that matches your climate and building type. We will also cover common mistakes, recordkeeping practices, and when to bring in outside expertise. By the end, you should have a clear mental model of how a finishing barn works as a system and the specific numbers you need to start sketching your own floor plan. ## At a Glance - **Space allowance**: Provide 8 to 10 square feet per pig for pigs grown to 270 to 280 pounds. For heavier market weights near 300 pounds, plan on 9.5 to 11 square feet per pig. - **Pen size**: Keep pens between 10 and 20 feet wide and 12 to 30 feet long. A common starting point is 20 to 30 pigs per pen, with 10 to 12 feet of solid flooring at the feeder and drinker area. - **Stocker density**: Weaned pigs at 40 to 50 pounds can start at 4 to 5 square feet per pig if you sort or move them once during the finishing period. If you do not plan to sort, start at the final space allowance. - **Feeder space**: Provide 1 feeder opening (approximately 12 to 15 inches wide) for every 4 to 5 pigs when using a conventional dry feeder. For wet-dry feeders, one opening can serve 8 to 10 pigs. - **Water access**: Provide at least one nipple drinker per 10 to 12 pigs, or two cup drinkers per pen for groups up to 30. Place drinkers away from the lying area and at pig shoulder height. - **Ventilation minimums**: In cold weather, provide a minimum air exchange of 20 to 30 cubic feet per minute (CFM) per pig. In hot weather, plan for 200 to 300 CFM per pig, depending on tunnel ventilation design and ceiling height. - **Flooring**: Fully slatted floors are the most common for finishing barns. Use concrete slats with 0.75 to 1 inch slot widths for nursery pigs and 1 inch slots for finishing pigs. Plastic or wire mesh flooring works for nursery phases but is not durable for heavy finishing pigs. - **Alley width**: Provide a minimum 5 to 6 foot wide feed alley if you use a cart or small tractor. For skid steer access, plan on 8 to 10 feet. A 4 foot alley works for personnel only. - **Biosecurity**: Design for a clean-dirty line at the barn entrance, a boot wash station, and a dedicated loadout area that can be washed and disinfected between loads. ## Understanding Pig Growth and Space Needs Before you draw a single line on paper, you need to understand how pigs grow and how their space requirements change over the finishing period. A finishing barn is not a static environment. The pigs arrive at 40 to 60 pounds and leave at 270 to 300 pounds or more. Their weight increases five to six times during the grow-finish phase, and their space needs increase proportionally. Pigs are social animals with a defined hierarchy. When space is too tight, aggression increases, and lower-ranking pigs spend less time at the feeder and drinker. This leads to increased variation in body weight within the pen, which costs you money at market. The goal of space allocation is to provide enough room for every pig to eat, drink, lie down, and stand up comfortably without constant competition. The most widely used guideline for finishing pig space comes from the National Pork Board. Their recommendation is based on the allometric relationship between pig weight and floor space. The formula is: Space per pig (square feet) = k x (body weight in pounds)^0.667 Where k is a constant that depends on the desired level of performance. For maximum growth rate, k is approximately 0.033 to 0.035. For maximum profit considering feed costs and facility costs, k is often set at 0.030 to 0.033. To make this practical, here are the space allowances for common market weights: | Market Weight (lb) | Minimum Space (sq ft) | Recommended Space (sq ft) | |---|---|---| | 250 | 6.5 | 7.5 | | 270 | 7.0 | 8.0 | | 280 | 7.5 | 8.5 | | 300 | 8.0 | 9.5 | | 320 | 8.5 | 10.5 | These numbers assume fully slatted flooring. If you use solid concrete floors with bedding, you need to add 10 to 15 percent more space because the lying area and the dunging area are not clearly separated. Pigs on solid floors also need more space to keep the sleeping area clean. The key decision is whether you will sort pigs during the finishing period. If you plan to move the largest pigs out early or re-sort pens at mid-finish, you can start pigs at a lower space allowance and grow into the final space. For example, you might start 50 pound pigs at 4.5 square feet per pig and then reduce pig numbers or move pigs at 150 pounds so that by market weight they have the full 8.5 square feet. This approach increases barn utilization but requires an extra handling event and careful planning. Most producers who are new to finishing barns should keep it simple. Start at the final space allowance and do not sort. The cost of an extra few weeks of partial barn occupancy is usually less than the cost of reduced performance from overcrowding or the labor and stress of sorting. ## Barn Types and Basic Layout Options There are three main types of finishing barn layouts: totally enclosed with mechanical ventilation, naturally ventilated with curtain sides, and hoop barns or other low-cost structures. Each has its place depending on your climate, budget, and management style. ### Totally Enclosed Mechanically Ventilated Barns These are the most common for large-scale production. The barn is fully insulated, sealed, and uses fans and inlets to control airflow. They offer the most precise environmental control and are the best choice for extreme climates, both hot and cold. Construction costs are higher, but you gain the ability to manage temperature within a narrow range year-round. A typical mechanically ventilated finishing barn is 40 to 50 feet wide and 200 to 400 feet long. The interior is divided into two rows of pens along each side wall, with a central feed alley. This configuration minimizes the distance pigs have to travel to the feeder and allows the feed alley to serve both sides. ### Naturally Ventilated Curtain-Side Barns Curtain-side barns use adjustable side curtains and ridge vents to manage airflow. They are less expensive to build and operate because they do not require as many fans. They work well in moderate climates where temperature swings are not extreme. In cold weather, the curtains close down to a small opening, and in hot weather, they open fully to allow breeze through the building. The main limitation of curtain-side barns is that you have less control over temperature and airflow. In very hot, still weather, you may need to add stirring fans or a tunnel ventilation system to keep pigs comfortable. In very cold, windy weather, drafts can be a problem near the side walls. ### Hoop Barns and Low-Cost Structures Hoop barns are Quonset-style structures with a steel frame and a fabric or plastic cover. They are the lowest cost option per pig space and are popular for smaller producers and for pigs raised with bedding. The floor is typically solid concrete or packed dirt with straw or cornstalk bedding. Manure is handled as a solid, either composted in place or removed with a skid steer. Hoop barns require more labor for bedding and manure removal. They also have less environmental control, so pig performance can suffer during extreme weather. However, for a producer who has abundant bedding material and is willing to manage the extra labor, hoop barns can be a profitable entry into finishing. ## Designing the Floor Plan The floor plan is the heart of your barn design. It determines traffic flow, labor efficiency, and pig comfort. Start by deciding on your target barn capacity and work backward to the building dimensions. ### Step 1: Determine Barn Capacity Decide how many pigs you want to finish at one time. This is usually driven by your wean-to-finish supply, your market contract, or your feed supply. A common starting point for an independent producer is 1,000 to 2,000 head at a time. Larger operations may run 5,000 to 10,000 head in multiple barns. For this example, we will plan a barn for 1,200 pigs at a time, with a target market weight of 280 pounds. ### Step 2: Calculate Total Floor Space Using the recommended space allowance of 8.5 square feet per pig for 280 pound pigs: 1,200 pigs x 8.5 sq ft = 10,200 square feet of pen space Add 15 percent for alleys, feeder space, and other non-pen areas: 10,200 sq ft x 1.15 = 11,730 square feet of total building area ### Step 3: Choose Building Dimensions A common width for a mechanically ventilated finishing barn is 40 to 50 feet. Let us use 44 feet wide. Divide the total area by the width to get the length: 11,730 sq ft / 44 ft = 267 feet So a barn that is 44 feet wide and 270 feet long would give you the space you need. This is a manageable length for a single building. If you prefer a shorter, wider building, you could go 60 feet wide and 200 feet long, but the wider building will require a different ventilation design. ### Step 4: Divide Into Pens With a 44 foot wide barn, you have several options for pen layout. The most common is two rows of pens along each side wall, with a central feed alley. This gives you four rows of pens total. If the building is 44 feet wide, each pen can be 10 to 12 feet deep (from the alley to the side wall), leaving a 6 to 8 foot central alley. Let us plan for pens that are 12 feet deep and 20 feet wide. The pen area per pen is: 12 ft x 20 ft = 240 square feet At 8.5 square feet per pig, this pen holds: 240 sq ft / 8.5 sq ft per pig = 28 pigs With 1,200 pigs, you need: 1,200 / 28 = 43 pens The building is 270 feet long. With 20 foot wide pens, you can fit 13 pens along each side of the building (13 x 20 = 260 feet), leaving 10 feet for the end alley and equipment room. With four rows of pens (two on each side of the central alley), you get: 13 pens per row x 4 rows = 52 pens This gives you capacity for: 52 pens x 28 pigs = 1,456 pigs That is more than you need, so you can either make the pens slightly larger or build a shorter barn. For this example, we will keep the 44 x 270 foot barn and plan for 52 pens at 28 pigs each, which gives you a little extra capacity for mortality or sorting. ### Step 5: Place Alleys and Service Areas The central feed alley should be at least 6 feet wide to allow a feed cart or small tractor to pass. If you plan to use a skid steer for cleaning between groups, make it 8 to 10 feet wide. The alley runs the full length of the building. At one end of the building, include a service room with the electrical panel, ventilation controller, and feed system controls. At the other end, or on the side, include a loadout area where pigs can be loaded onto trucks. The loadout area should have a chute or ramp that can be raised to match truck deck height. ## Pen Design and Configuration Pen design is about more than just wall placement. The internal layout of each pen determines how pigs use the space, where they dung, and how easy they are to handle. ### Pen Dimensions The ideal pen is slightly longer than it is wide. A pen that is 12 feet deep and 20 feet wide has a length to width ratio of 1.67 to 1. This gives pigs a clear lying area at the back of the pen and a dunging area near the front, close to the alley. If the pen is too wide and shallow, pigs tend to dung in the middle, which keeps the lying area wet. For fully slatted floors, the pen shape matters less because the dung falls through the slats. However, you still want a distinct lying area. Place the feeder and drinker at the front of the pen, near the alley, and keep the back of the pen as a clean, dry lying area. ### Pen Partitions Pen partitions should be solid on the bottom 2 to 3 feet to prevent nose-to-nose contact between adjacent pens. This reduces disease transmission and aggression. The top portion can be open or have vertical bars to allow air movement and visibility. Use sturdy materials. Pigs are strong and will test the partitions. Concrete or heavy-duty steel panels are the most durable. Avoid wood, which absorbs moisture and bacteria and is difficult to clean. ### Gates and Doors Each pen needs a gate that opens to the alley. The gate should be at least 3 feet wide for easy pig movement. Use a gate that can be opened from both sides and that latches securely. Sliding gates are safer than hinged gates because they do not swing into the alley and create a hazard. Consider adding a sorting panel or a smaller gate within each pen. This allows you to separate a few pigs for treatment or sorting without moving the entire group. ### Flooring Flooring is one of the most important decisions in the barn. Fully slatted concrete is the industry standard for finishing barns. It provides a clean surface, allows manure to fall through to the pit below, and is durable for many years. Concrete slats come in various widths and slot spacings. For finishing pigs, use slats that are 5 to 6 inches wide with 1 inch gaps. The gap should be wide enough to allow manure to pass through but narrow enough to prevent hoof injuries. If you will also use the barn for the nursery phase, use 0.75 inch gaps for the smaller pigs. Plastic or fiberglass slats are also available. They are lighter and easier to handle but are more expensive and can become slippery when wet. They are more common in nursery barns than in finishing barns. If you use partially slatted floors, place the slatted area at the front of the pen, where the feeder and drinker are located. The back 4 to 6 feet of the pen can be solid concrete, which gives pigs a comfortable lying area. The solid area must be cleaned regularly, which adds labor. ## Ventilation System Design Ventilation is the most critical system in a finishing barn. Pigs produce a large amount of heat and moisture, and they are sensitive to ammonia and other gases from the manure pit. Poor ventilation leads to respiratory disease, reduced feed intake, and poor growth. The ventilation system has three jobs: remove heat, remove moisture and gases, and provide fresh oxygen. The system must do all three in both cold and hot weather. ### Basic Principles In cold weather, the goal is to remove moisture and gases while conserving heat. The minimum ventilation rate is typically 20 to 30 CFM per pig, depending on pig size and outside temperature. This air exchange removes moisture from respiration and manure and keeps ammonia levels below 10 to 15 parts per million. In hot weather, the goal is to remove heat. Pigs do not sweat, so they rely on evaporative cooling from their respiratory tract and on conductive cooling from the floor and air movement. The ventilation rate increases as temperature rises, reaching 200 to 300 CFM per pig in extreme heat. The transition between minimum and maximum ventilation is managed by a controller that adjusts fan speed and inlet openings based on temperature and humidity sensors. ### Mechanical Ventilation For a fully enclosed barn, you have two main options: negative pressure and tunnel ventilation. In a negative pressure system, fans on one end of the building pull air out, creating a slight vacuum. Fresh air enters through inlets on the opposite end or on the side walls. The inlets are adjustable to control air speed and direction. In cold weather, the inlets direct air up toward the ceiling, where it mixes with warm air before falling down to pig level. This prevents cold drafts on the pigs. In a tunnel ventilation system, fans are placed on one end wall and inlets on the opposite end wall. Air moves in a straight line down the length of the building, creating a wind chill effect that helps pigs cool in hot weather. Tunnel ventilation is effective in barns longer than 150 feet. The air speed at pig level should be 300 to 500 feet per minute for good cooling. Most large finishing barns use a combination system. They have minimum ventilation fans and inlets for cold weather, plus tunnel fans and large inlets for hot weather. The controller switches between modes based on temperature. ### Natural Ventilation Naturally ventilated barns rely on the wind and the stack effect (warm air rising) to move air. The side curtains open and close to adjust airflow. A ridge vent at the peak of the roof allows warm, moist air to escape. The key to successful natural ventilation is a building that is properly oriented to the prevailing wind and has adequate ridge opening. The ridge vent should be continuous along the full length of the building and sized at about 1 inch of opening for every 10 feet of building width. Natural ventilation works best in moderate climates. In very hot weather, you may need to add stirring fans or a misting system. In very cold weather, the curtains close down to a small opening, and you rely on the ridge vent for minimum ventilation. This can be tricky to manage, because too little opening leads to moisture buildup and too much leads to cold drafts. ### Manure Pit Ventilation If you have a deep pit under a slatted floor, the pit also produces gases, primarily ammonia and hydrogen sulfide. These gases are heavier than air and can accumulate in the pit. You need a pit ventilation system that draws air down through the slats and exhausts it outside. In a mechanically ventilated barn, pit fans are placed on the end wall below floor level. They run continuously at a low rate to remove gases. In a naturally ventilated barn, the pit is vented through the ridge or through a separate exhaust pipe. Never enter a manure pit without proper safety equipment. Hydrogen sulfide is toxic and can be fatal at low concentrations. The pit should be ventilated before entry, and you should always use a gas detector and a safety harness. ## Feeding System Layout The feeding system is the second most important system in the barn. Pigs need constant access to fresh feed, and the feed delivery system must be reliable and easy to maintain. ### Feed Storage and Delivery Feed is typically stored in a bin or silo outside the barn. A flexible auger system moves feed from the bin to the feeders inside the barn. The auger runs along the feed alley and drops feed into each feeder through a downspout. The feed bin should be sized to hold at least a 7 to 10 day supply of feed. For 1,200 pigs eating an average of 6 pounds per day, the daily feed use is 7,200 pounds. A 10 day supply is 72,000 pounds, or about 36 tons. A 40 ton bin would be a reasonable choice. The auger system should be sized to fill all feeders within a reasonable time. A 4 inch auger moves about 800 pounds per hour. For 52 feeders, this may take several hours. You can reduce fill time by using a larger auger or by filling feeders in stages. ### Feeder Types There are two main types of feeders for finishing pigs: dry feeders and wet-dry feeders. Dry feeders hold pelleted or meal feed in a hopper and dispense it into a trough. The pig pushes a paddle or steps on a pedal to release feed. Dry feeders are simple, reliable, and relatively inexpensive. The main drawback is that pigs can waste feed by rooting it out of the trough. Wet-dry feeders mix feed and water in the trough, creating a gruel that pigs eat readily. They reduce feed waste and dust, and they encourage higher feed intake. They also require a water line to each feeder. Wet-dry feeders are more expensive but often pay for themselves in improved feed conversion. Whichever feeder you choose, match the feeder size to the number of pigs per pen. A conventional dry feeder with a 12 to 15 inch wide opening serves 4 to 5 pigs. For a 28 pig pen, you need 6 to 7 feeder openings. This is typically a single feeder with multiple openings along its length. ### Feeder Placement Place the feeder at the front of the pen, near the alley. This keeps the feed alley clean and makes it easy to check feed levels. The feeder should be positioned so that pigs can approach from both sides. A feeder that is accessible from only one side requires more feeder space per pig. The feeder should be adjustable so that the feed flow can be matched to pig size and feed intake. Check feeders daily and adjust the flow to minimize waste. Feed that accumulates in the trough is a sign that the flow is too high. Feed that is always empty is a sign that the flow is too low. ## Water System Layout Pigs need clean, fresh water at all times. Water intake is directly related to feed intake, and any restriction in water access will reduce growth. ### Water Requirements A finishing pig drinks 2 to 4 gallons of water per day, depending on temperature, feed intake, and weight. In hot weather, water consumption can double. The water system must be sized to meet peak demand. Each pen should have at least two drinkers, placed at opposite ends of the pen if possible. This prevents [dominant](/blog/careers/dominant-definition-biology) pigs from guarding the water source and allows smaller pigs to drink without competition. ### Drinker Types and Placement Nipple drinkers are the most common. They are simple, hygienic, and reliable. The nipple should be placed at pig shoulder height. For a 40 to 60 pound pig, the nipple should be 14 to 18 inches above the floor. For a 280 pound pig, it should be 24 to 30 inches above the floor. Adjustable drinkers that slide up and down on a bracket are ideal because they can be raised as pigs grow. Cup drinkers are another option. They fill a small cup with water that the pig drinks from. They reduce water waste and are easier for small pigs to use, but they require more cleaning. Place drinkers over the slatted area, not over the solid lying area. This keeps the lying area dry. If the drinker is over solid concrete, the spilled water will create a wet, muddy area that increases the risk of skin infections and makes the pen harder to clean. ### Water Quality and Flow Rate Test your water source before building the barn. Water with high mineral content, especially iron, sulfur, or nitrates, can reduce water intake and cause digestive problems. The flow rate at each drinker should be at least 1 pint per minute for finishing pigs. Low flow rates cause pigs to spend more time at the drinker and reduce feed intake. The water lines should be sized to deliver the required flow to all drinkers simultaneously. A 1 inch line can typically serve 50 to 100 drinkers, depending on the length of the line and the water pressure. Install a pressure regulator at the barn entrance and check it regularly. ## Manure Handling and Storage Manure management is a major consideration in barn design. The system you choose affects building layout, ventilation, and daily labor. ### Deep Pit Storage The most common system for large finishing barns is a deep pit, 8 to 10 feet deep, under the slatted floor. Manure falls through the slats and is stored in the pit until it is pumped out and applied to fields. This system requires no daily labor and keeps the barn clean. The pit is typically pumped once or twice a year, depending on capacity and crop needs. The pit must be designed to handle the volume of manure produced. A 280 pound pig produces about 1.4 cubic feet of manure per day. For 1,200 pigs, that is 1,680 cubic feet per day. Over 6 months (180 days), that is 302,400 cubic feet, or about 2.26 million gallons. A pit that is 44 feet wide and 270 feet long with 8 feet of storage depth holds about 95,000 cubic feet. You would need to pump the pit roughly every 3 months, or you need a larger pit or more frequent pumping. Deep pits are expensive to build but save labor over the life of the barn. They also allow you to store manure until the best time for field application. ### Pull-Plug and Flush Systems Some barns use a shallow pit with a pull-plug or flush system. In a pull-plug system, the pit has a plug at one end that is pulled to drain the manure into a storage lagoon or tank. This is done every few weeks. In a flush system, water is released into the pit to flush the manure into a storage structure. Flush systems use a lot of water, which increases the volume of manure to handle. These systems reduce the amount of manure stored under the barn, which can reduce odor and gas levels. However, they require more daily management and a separate storage structure. ### Solid Manure Systems Hoop barns and some smaller operations use solid manure systems. Pigs are bedded with straw or cornstalks, and the manure and bedding are removed as a solid. This requires daily or weekly bedding and periodic removal with a skid steer or loader. Solid manure systems require more labor but produce a valuable compost that can be used on fields or sold. They also have lower construction costs because there is no pit under the barn. ## Environmental Control and Controller Setup Modern finishing barns use an electronic controller to manage ventilation, heating, and alarms. The controller is the brain of the barn, and getting it set up correctly is essential. ### Temperature Settings Pigs are most comfortable in a narrow temperature range. For finishing pigs, the thermoneutral zone is roughly 60 to 75 degrees Fahrenheit. At temperatures above 80 degrees, pigs reduce feed intake to lower their heat production. At temperatures below 50 degrees, they increase feed intake to stay warm, which reduces feed efficiency. The controller should be set to maintain the barn at the target temperature for the pig's weight. A common starting point is 75 degrees for a 50 pound pig, dropping to 65 degrees for a 280 pound pig. The controller should adjust the ventilation rate to maintain this temperature. ### Humidity and Air Quality Temperature is not the only factor. Humidity affects how well pigs can cool themselves. High humidity reduces evaporative cooling, making pigs feel hotter than the actual temperature. The controller should monitor humidity and increase ventilation when it rises above 60 to 70 percent. Ammonia is a constant concern in a barn with a manure pit. The controller should be set to increase ventilation if ammonia levels rise above 10 to 15 parts per million. You can also install an ammonia sensor that alerts you to high levels. ### Alarm Systems A ventilation failure can kill pigs in a matter of hours, especially in hot weather. Install a reliable alarm system that alerts you to power failure, fan failure, or high temperature. The alarm should be connected to a phone or pager so you can respond quickly. Have a backup generator that can power the ventilation system in case of a power outage. Test the generator monthly and keep it fueled and serviced. ## Biosecurity and Loadout Design Biosecurity is a critical part of barn design. The layout of the barn should make it easy to follow biosecurity protocols and hard to accidentally spread disease. ### Clean-Dirty Line Every barn should have a clear clean-dirty line at the entrance. The dirty side is the outside, where boots and clothing may be contaminated. The clean side is the inside, where the pigs live. The line should be marked on the floor, and you should have a bench or barrier that you step over or sit on when changing boots. Provide a boot wash station at the entrance with a disinfectant solution. Boots should be cleaned and disinfected before entering the clean side. Provide coveralls or a clean set of clothes that stays in the barn. ### Loadout Area The loadout area is where pigs are loaded onto trucks for market. This is a high-risk area because trucks can carry disease from other farms. The loadout should be designed so that the truck driver does not enter the barn and so that the loadout area can be washed and disinfected between loads. The loadout chute should be at the end of the barn, away from the main entrance. It should have a door that can be closed and locked when not in use. The chute should be made of non-porous material that can be pressure washed and disinfected. ### All-In All-Out The most important biosecurity practice is all-in all-out pig flow. This means that all pigs in a barn are the same age, enter at the same time, and leave at the same time. The barn is then washed, disinfected, and left empty for a period of 7 to 14 days before the next group arrives. All-in all-out is easier to manage with a single barn. If you have multiple barns, schedule them so that each barn is emptied and cleaned before the next group arrives. Do not mix ages of pigs in the same barn, as this increases the risk of disease spread. ## Common Mistakes in [Finishing Barn Design](/knowledge/animal-farming/farm-management/swine-finishing-barn-design-ventilation-manure) Even experienced producers make mistakes when designing a new barn. Here are the most common ones to avoid. ### Underestimating Space Needs The most common mistake is providing too little space per pig. Producers often plan for the space needs at the start of the finishing period, when pigs are small, and do not account for their final weight. This leads to overcrowding in the last few weeks before market, which reduces growth and increases variation. Always plan for the final market weight, not the starting weight. It is better to have slightly too much space than not enough. ### Poor Feeder and Drinker Placement Placing the feeder and drinker too close together can cause competition and waste. Pigs that are eating will block access to the drinker, and pigs that are drinking will block access to the feeder. Keep the feeder and drinker at least 3 to 4 feet apart. Placing the drinker over solid concrete is another common mistake. The spilled water creates a wet area that becomes a source of odor and disease. Always place drinkers over slatted floors. ### Inadequate Ventilation in Hot Weather Many producers focus on cold weather ventilation and underestimate the heat load in summer. A finishing pig produces a lot of heat, and if the ventilation system cannot remove it, the pigs will reduce feed intake and growth will suffer. Design the ventilation system for the hottest weather you expect, not the average. Add extra tunnel fans or evaporative cooling if you are in a hot climate. ### Ignoring the Manure Pit The manure pit is easy to ignore because it is out of sight. But pit management affects air quality, pig health, and the environment. A pit that is overfull can release dangerous gases, and a pit that is not pumped regularly can overflow. Plan the pit size and pumping schedule before you build. Know how much manure your pigs will produce and how often you need to pump. ### Skimping on Alleys and Access Narrow alleys save floor space but cost you time and labor every day. A feed alley that is too narrow for a feed cart means you carry feed by hand. A loadout area that is too small makes loading pigs stressful and slow. Plan for the equipment you will use, not the equipment you have today. A 6 foot feed alley is the minimum for a cart. An 8 foot alley is much more comfortable and allows for a small tractor. ## Monitoring and Recordkeeping Once the barn is built and stocked, your job is to monitor performance and keep records. Good records help you identify problems early and make better decisions. ### Daily Checks Walk the barn at least once a day, preferably twice in hot weather. Look for: - Pigs that are lying in the dunging area, which indicates the lying area is too warm - Pigs that are huddled together, which indicates they are cold - Pigs that are panting, which indicates they are too hot - Feeders that are empty or overflowing - Drinkers that are not working - Wet spots on the floor that indicate a leak or a problem with the drinker - Any pigs that appear sick, injured, or unthrifty Check the ventilation system. Listen for fans that are not running, and check the controller for error messages. Check the ammonia level by smell or with a gas detector. ### Performance Records Keep records of: - Number of pigs placed and date of placement - Average starting weight - Feed delivered to each barn or pen - Mortality and culls - Average ending weight and date of sale - Feed conversion (pounds of feed per pound of gain) A simple spreadsheet is sufficient for most producers. Calculate feed conversion for each group and compare it to previous groups. If feed conversion worsens, investigate the cause. It could be a feed problem, a health problem, or an environmental problem. ### Weekly or Monthly Review Set aside time each week or month to review your records. Look for trends. Is the average daily gain declining? Is mortality increasing? Is feed intake lower than expected? These trends can alert you to problems before they become serious. Compare your performance to industry benchmarks. The National Pork Board publishes benchmarks for average daily gain, feed conversion, and mortality. If you are below these benchmarks, look for ways to improve. ## When to Call a Veterinarian or Extension Agent You should have a relationship with a swine veterinarian before you need one. A veterinarian can help you design a herd health plan, recommend vaccines, and advise on biosecurity. If you do not have a veterinarian, contact your state pork producers association or your extension service for a referral. Call your veterinarian immediately if you see: - A sudden increase in mortality - Multiple pigs with the same signs of illness, such as fever, coughing, or diarrhea - Pigs that are off feed for more than 24 hours - Any signs of a reportable disease, such as [African swine fever](/knowledge/bioinformatics/african-swine-fever-computational-models-for-early-detection-and-spread-prediction-in-wild-boar-populations), foot-and-mouth disease, or classical swine fever Reportable diseases must be reported to the USDA APHIS and your state veterinarian. Do not wait to see if the problem resolves. Early reporting can prevent the spread of a serious disease. Your local cooperative extension service is also a valuable resource. Extension agents can help with barn design, ventilation, nutrition, and manure management. They can also connect you with other producers who have experience with finishing barns. ## Frequently Asked Questions ### How much space does a finishing pig need? A finishing pig needs 8 to 10 square feet of floor space, depending on the final market weight. For pigs marketed at 270 to 280 pounds, provide 8 to 8.5 square feet per pig. For pigs marketed at 300 pounds or more, provide 9.5 to 11 square feet per pig. These recommendations assume fully slatted floors. If you use solid floors with bedding, add 10 to 15 percent more space. ### What is the best barn width for a finishing barn? A width of 40 to 50 feet is the most common and practical for a mechanically ventilated finishing barn. This allows for two rows of pens along each side wall with a central feed alley. A 44 foot wide barn with 12 foot deep pens leaves a 6 to 8 foot central alley. Wider barns of 60 feet or more are possible but require a different ventilation design and are less common. ### How many pigs should be in each pen? A group of 20 to 30 pigs per pen is a good balance between social stability and efficient use of space. Smaller groups of 10 to 15 pigs are easier to manage but use more feeder and drinker space per pig. Larger groups of 40 to 50 pigs are more efficient but can lead to more aggression and variation in weight. For most producers, 25 to 30 pigs per pen is the sweet spot. ### Should I use fully slatted or partially slatted floors? Fully slatted floors are the most common choice for finishing barns because they require the least labor and keep the barn clean. The manure falls through the slats into a pit below, so there is no daily scraping or cleaning. Partially slatted floors with a solid lying area can reduce building cost and provide a more comfortable lying surface, but they require daily cleaning of the solid area. For most producers, fully slatted floors are the better choice. ### How often should I pump the manure pit? The pumping schedule depends on the pit size and the number of pigs. A general rule is to pump the pit before it is more than two-thirds full. For a deep pit under a 1,200 head barn, this may be every 3 to 6 months. Monitor the pit level regularly and keep a record of pumping dates. Pump in good weather when the manure can be applied to fields immediately. ### What is the ideal temperature for a finishing barn? Finishing pigs are most comfortable between 60 and 75 degrees Fahrenheit. The ideal temperature decreases as pigs grow. A 50 pound pig prefers about 75 degrees, while a 280 pound pig prefers about 65 degrees. At temperatures above 80 degrees, pigs reduce feed intake to lower heat production. At temperatures below 50 degrees, they increase feed intake to stay warm, which reduces feed efficiency. ### How do I know if my ventilation is working properly? Monitor the pigs, not just the equipment. If pigs are lying in the dunging area, the barn is too warm. If they are huddled together, it is too cold. If there is a strong ammonia smell, the ventilation rate is too low. Use a gas detector to measure ammonia and carbon dioxide levels. Ammonia should be below 10 to 15 parts per million, and carbon dioxide should be below 3,000 parts per million. ### Can I convert an existing barn into a finishing barn? Yes, many producers convert dairy barns, horse barns, or other structures into finishing barns. The key is to assess the existing structure for ventilation, drainage, and accessibility. You may need to add insulation, install new ventilation equipment, and modify the floor for manure handling. It is often more expensive to remodel an existing barn than to build new, so get a detailed cost estimate before you start. ## Related Farming Guides This section will be populated with links to related farming guides on swine production, barn design, and herd health as they are published. ## Related Clinical & Scientific Guides * [Pig Enrichment Programs and Behavior Monitoring](/knowledge/animal-farming/swine/pig-enrichment-programs-and-behavior-monitoring) * [Swine Handling Facility Design for Safe Pig Movement](/knowledge/animal-farming/swine/swine-handling-facility-design-safe-pig-movement) * [Swine Feeding Management for Grow-Finish Pigs](/knowledge/animal-farming/swine/swine-feeding-management-for-grow-finish-pigs) ## References - National Pork Board: https://www.pork.org/ - USDA APHIS Swine Health: https://www.aphis.usda.gov/livestock-poultry-disease/swine - FAO Pig Production: https://www.fao.org/pig-production-and-products/en/ - FAO Animal Production and Health: https://www.fao.org/animal-production/en/ - WOAH (World Organisation for Animal Health): https://www.woah.org/en/home/ > This article is educational and is not a substitute for veterinary diagnosis, treatment, public-health guidance, or regulatory reporting.